New to building water profiles, what did I do wrong?

[BrewerJack]

So I have been brewing for about 13 years and have only just started trying to nail down water profiles, but I am just not groking it and my beer is suffering for it.

So here is my recipe for 5 gallons, using RO water throughout:

12 lbs Maris Otter
12 oz Crystal 20
12 oz Crystal 120
12 oz Roasted Barley (300)
8 oz Chocolate Malt (350)
1 oz Warrior(15.7) @ 60m
1 Tablet Whirlfloc @ 15m
12 oz Ibarra Mexican Chocolate @ 5m
2 pkg Nottingham dry yeast (I love this stuff)

Mash In: 4.6gal @156 for 45m
Mash Out: 1.85gal @168 for 10m
Fly Sparge: 2.3gal @ 168

Mash Salt Additions:
4g Chalk
3g Baking Soda
1.9g Epsom Salt
1.8g Calcium Chloride

Sparge Additions:
.5g Calcium Chloride
.5g Epsom Salt

So it comes out with a distinct astringent chemically taste.

Thanks for the help.

 

[mabrungard]

1.9 g Epsom salt in 4.6 gal of water is only about 9 ppm Mg, so that is not a problem. The baking soda addition isn't excessive either and probably only adds about 30 ppm sodium to the final wort.

I do question the chalk addition, since it doesn't really add anything to the mash because it doesn't dissolve in a timely manner. I'm assuming you are adding the baking soda and chalk to avoid the mash pH from falling too low. However, only the baking soda is probably doing anything in that respect and its still possible that the mash pH was lower than desired. That can create some sharpness in the resulting beer flavor.

I see that the roast and crystal additions are significant and its very possible that the grist is very acidic. Now I see why you really needed that alkalinity addition. Hopefully you had a pH meter, but I'm pretty sure that your wort was probably at a lower than desired pH and that doesn't tend to contribute a sharpness in roasty beers that may not have been what you are looking for. Using more baking soda and forgetting the chalk addition will be more successful in controlling the pH drop in this wort. You will also want to boost the calcium addition via gypsum and calcium chloride since chalk won't be part of the equation.

 

[BrewerJack]

Thanks for the info.

I actually used Bru'n Water to manage these additions.

I don't have a pH meter yet, I have been using the approximations on the Bru'n Water sheet. I also forgot to add a mash addition to my original post which is where I think I am getting my off taste from...

I added 5.3mL of 88% lactic to the mash.

Did I **** that up?

Also I found the saved Bru'n Water profile that I can send you a link to if you'd like.

 

[ajdelange]

So it comes out with a distinct astringent chemically taste.

Not too surprising. The culprits here are probably (and we must always say 'probably' unless we are there with pH meter in hand) the alkali additions. The grist you listed actually needs a bit of acid - not alkali. With just the calcium chloride addition you might expect a mash pH a bit over 5.6 at room temperature which is marginally OK though many would encourage lowering it a bit. This assumes you chose Munton's M.O. Had you chosen Crisp's the expected pH would be a bit about 5.5 at room temperature which most would consider OK. The interesting twist here is that at 50 °C both these malts would lead to about the same mash pH (around 5.26). If you used Fawcett's or some other maltsters M.O. then I can't say but wouldn't expect things to be too much different. In any case it is not expected that any alkali would be needed or wanted.

The obvious question is as to what happens if you add some anyway. Using the Crisp MO as a baseline we'd have an estimated room temperature pH of 5.50. The bicarbonate would suck up 31 mEq of protons which is just about the amount contributed by the two black grains. IOW they are effectively nullified in terms of pH control and the pH would, therefore, go up about 0.1 unit. Not a good thing but not a terribly bad thing either. The bicarbonate is taking you in the wrong direction but not too far. Now the chalk (calcium carbonate) is a different matter. It would absorb 75 mEq of protons and thus (if things were linear) be expected to raise the mash pH by over 0.2 units. As things are not linear the combined effect of the chalk and bicarbonate would be to raise the pH to 5.77 (not quite 5.50 + 0.1 + 0.2) but still high enough to get us into the 'muddy' flavors range. The 'good news' about chalk is that it doesn't dissolve (which is why when you actually do need alkali you should pick something else) and so is, let's say, 50% effective. In that case you would expect it to raise pH by 0.1 unit rather than 0.2. It's effect combined with the bicarbonate is 5.66. Too high but not disastrously so. Flavors will be duller than they should be if not perhaps yet muddy.

The 'bad news' is that the unreacted calcium carbonate stays in the mash and continues to react as time passes as the wort is still acidic if not as acidic as we'd like it to be. Throughout all the remaining steps of the mash, the time in the lauter tun and even in the kettle that chalk is still there continuously raising pH. We assume that by the time lauter is complete the chalk particles are fine enough that they flow through the filter bed though in fact some larger particles might get trapped. The result of all this is that the chalk doesn't do all its damage in the mash but saves some punch to ruin the kettle wort and beer in the fermenter. That chemical taste you reference may be unreacted chalk and certainly organic beer flavors will not be what they should be either.

In summary:
1. Don't use alkali unless you need it (you don't here).
2. Where you do need it don't use chalk.

 

[ajdelange]

Just spotted your second post: the addition of the 5.3 mL lactic acid would supply 60 mEq of the 74 potentially absorbed by the chalk addition. IOW, the two more or less cancel each other out and mash pH might be expected to be about 5.6 - again on the borderline of too high.

There is absolutely no point in adding an acid and a base (from the pH control perspective) as they neutralize one another. Lactic acid is (with respect to mash pH) a strong acid and so might cause more of the chalk to react though even with stronger acids carbonate reactions are slow.

 

[mabrungard]

I'm hoping that AJ just mis-read the grist composition above since it is VERY apparent that it is an EXTREMELY acidic grist and doesn't need a drop of acid in the mash when the brewer started with RO water.

Having worked and tested grists similar to the OP's grist, I'm familiar with the very low pH that will be produced. With straight RO water, I estimate that the grist pH will easily fall into the 5.2 range, which tends to create a sharper flavor in roast dominant beers. The OP's unfortunate lactic acid addition just compounded the pH problem and likely pushed the mash under 5.0.

While I appreciate AJ's efforts with his mash pH model, this is an area where I am now positive that it fails. AJ and I are aware that the same modeling effort was conducted by Breiss and they could not craft an acceptable model either that properly models the low pH excursion with significant crystal and roast malt additions. I agree that those methods should work, however the evidence is that there is something else in the chemistry that is not being accounted for. Fortunately, the entirely empirical model used in Bru'n Water takes that response into account.

Keep working AJ, you will find it eventually.

 

[Tutsbrew]

Just spotted your second post: the addition of the 5.3 mL lactic acid would supply 60 mEq of the 74 potentially absorbed by the chalk addition. IOW, the two more or less cancel each other out and mash pH might be expected to be about 5.6 - again on the borderline of too high.

There is absolutely no point in adding an acid and a base (from the pH control perspective) as they neutralize one another. Lactic acid is (with respect to mash pH) a strong acid and so might cause more of the chalk to react though even with stronger acids carbonate reactions are slow.

I'm no chemist and I did not stay at a Holiday Inn Express recently, but is it possible that since the chalk was not dissolved into the water (unless OP used CO2 to do that and didn't disclose) and the large acid addition likely did dissolve, that the resulting pH was in fact very acidic resulting in the "acrid" taste?

 

[BrewerJack]

Basically what I need to do is get a god dang pH meter instead of throwing from the hip with what Bru'n Water uses as estimations. I also may be using Bru'n Water wrong when the acid addition comes in to play. I think with my calculations on Bru'n Water, it said this was a 5.6pH mash.


The way I add my salts is that I add them to half the grist in the MLT then add the other half of the grist and mix thoroughly before adding any water. Once I mash in I do another thorough mixing.

 

[ajdelange]

I'm hoping that AJ just mis-read the grist composition..

No. Just checked. We can go through the components:

5.45 kg (81.4%) Crisp Maris Otter:
DI pH 5.69
Buffering at pHDI: -46.6 mEq/kg-pH
Linear Approximation to proton deficit at pH 5.5: 48.1
Proton Deficit to pH 5.5: 49.4
Data Source: Measured in Lab

0.34 kg (5.1%) 20L Crystal Malt:
DI pH 5.22
Buffering Average: -29.6 mEq/kg-pH
Linear Approximation to proton deficit at pH 5.5: -2.8
Data Source: Kai Troester

0.34 kg (5.1%) 120L Crystal Malt:
DI pH 4.75
Buffering Average: -48.4 mEq/kg-pH
Linear Approximation to proton deficit at pH 5.5: -12.4
Data Source: Kai Troester

0.34 kg (5.1%) Roast Barley (300L)
DI pH 4.70
Buffering at pHDI: -35.4 mEq/kg-pH
Linear Approximation to proton deficit at pH 5.5: -9.7
Proton Deficit to pH 5.5: -16.8
Data Source: Measured in Lab

0.23 kg (3.4%) Chocolate Malt (300L)
DI pH 4.70
Buffering at pHDI: -76.4 mEq/kg-pH
Linear Approximation to proton deficit at pH 5.5: -13.9
Proton Deficit to pH 5.5: -14.4
Data Source: Lab Measurements on 600L Chocolate. Note: Kai's measurement on Black Patent: pHDI 4.62, Avg buffering: -41.5

...above since it is VERY apparent that it is an EXTREMELY acidic grist and doesn't need a drop of acid in the mash when the brewer started with RO water.

Add those proton deficits up with the small deficits for the RO water and small surfeit from the calcium chloride addition and you get 0. Thus the mash pH is 5.5 and it is VERY apparent than this mash isn't acidic at all. A pH of 5.5 might be a wee bit high for some who might choose to add some acid but I'd accept it. Now if I used Muntons I'd get, as noted, 5.6 and be tempted to add some but since I know the Muntons has an unusuall high pH glide (with temperature) I wouldn't.

Having worked and tested grists similar to the OP's grist, I'm familiar with the very low pH that will be produced. With straight RO water, I estimate that the grist pH will easily fall into the 5.2 range

I can't say that it isn't possible to produce a grist similar to the OP's which would exhibit pH as low as 5.2 but think it quite unlikely. The base malts here just have too much proton deficit, 49 mEq in the case of Crisp and 91 in the case of Muntons (because of it's higher pHDI - the buffering capacities are about the same). To get to 5.2 I would have to supply 127 mEq of protons to the base malt. If I substitute 5.1% sauermalz for the roast barley I can do that (it gives me 107 of those 127 with the rest coming from the other colored malts).

While I appreciate AJ's efforts with his mash pH model, this is an area where I am now positive that it fails.

I think you had better get some experimental evidence in hand after which you will revise that opinion. I would also caution making statements like this based on empirical evidence. Some great science has been done empirically but it doesn't have a leg to stand on against data.

AJ and I are aware that the same modeling effort was conducted by Breiss and they could not craft an acceptable model either that properly models the low pH excursion with significant crystal and roast malt additions.

That's Briess's problem, not mine.

I agree that those methods should work,

They do work if the malt and other mash component proton deficits/surfeits are modeled properly. Briess did not take the correct set of measurements. They measured to 5.7, they did not allow for the time factor, they did not account for the non linearity, and I have no idea how they actually did pH measurement, what temperature they used and so on. Kai did similar things. While his measurement technique was crude (acid strength determined from the label on hardware store HCl...) he at least did the titrations to 5.4 so that while non linearity isn't accounted for the total proton deficit calculated to pH near 5.4 isn't far off. I use his numbers where I don't have actual measurements (as indicated above) with pretty good results and his spreadsheet based on his measurements seems to be pretty good according to what I see here.

..however the evidence is that there is something else in the chemistry that is not being accounted for.

What is that evidence? In all the cases I have checked (and, of course, that number is finite) the model is not only robust if you believe in acid/base chemistry, but gives pretty good results given the disparities in, for example, the properties of Maris Otter (and, of course, any other malt). It takes a brave man to stand up in public and say 'Malt absorbs sulfuric acid in one way and lactic acid in another', I'll give you that.

Fortunately, the entirely empirical model used in Bru'n Water takes that response into account.

Analyst: When I mix this malt with this set of properties with that malt with that set of properties I expect to get this pH and when I take a measurement in the lab I get a result pretty close to that. This is a pretty good model.

Empiricist: Your model can't be right because when I do that I get a different answer.

Analyst: When you mix malts with the specific properties I laid out?

Empiricist: Well, I don't know about that. It was the same types of malt though.

Analyst: OK, so what were the properties of your malts?

Empiricist: I don't know.

Analyst: Then how can you possibly comment sensibly on the model?

Keep working AJ, you will find it eventually.

I have found it but clearly there is more work to do. The further I go the more obvious is that this is a good model (I just back checked against a dry stout I did a year or so ago using Crisp MO, roast barley and flaked barley, all of which I have subsequently measured and the model predicts pH within 0.01 of what I actually measured) but there are doubtless more details yet to reveal themselves I'm sure. I haven't hit the 'gotcha' yet and this is definitely not it. I've just unearthed the temperature glide disparity between malts. Considering this ought to give better room temperature pH estimates. Naturally, the more data I get on individual malts the deeper my understanding becomes and the more solid the model. My overall fear is that by the time we get into the difference between maltsters and crops and varieties and temperature glides and who knows what else that the data required to feed this robust model may be impractical to collect. It's already clear that the maltsters will have to do it.

A more interesting question is how you are able to get a pH as low as you do using malts anything like those that the OP is using here in the quantities he is using (19%). The colored malts would have to have potency like that of sauermalz rather than the colored malts that I, Kai, or even Briess measured. The alternative would have to be that the base malt has alkalinity way below what either I, Kai or Briess measured, or, I suppose, a combination of the above.

It would help in these discussions if you would reveal exactly how Bru'n water estimates mash pH but you seem reticent to do so other than to say "It's empirical". This implies doing a lot of mashes, measuring a lot of pH's and fitting curves to plots of some sort. I suspect the reticence stems from the fact that we might not find the approach very robust as indeed may be the case given our understanding of the number of combinations you would have to explore, imposed by variability in malt properties, in order to have any hope of significance.

One thought on why you might have seen low numbers is that you didn't wait for stabilization. When an acid malt (especially sauermalz) is placed in a mash the acid goes into solution quickly causing the pH to plummet (alarmingly the first couple of times I saw it). It can then take several minutes to crawl up to close to its equilibrium value and up to half an hour before it is within say, 0.02 pH of where it appears to be going.

 

[ajdelange]

I'm no chemist and I did not stay at a Holiday Inn Express recently, but is it possible that since the chalk was not dissolved into the water (unless OP used CO2 to do that and didn't disclose) and the large acid addition likely did dissolve, that the resulting pH was in fact very acidic resulting in the "acrid" taste?

Acrid taste is usually too much roast something. As he totals less than 10% of the chocolate and roast barley he shouldn't have that acrid taste unless one or the other of those roast things is overly ashy. As to the pH: if none of the chalk dissolves the pH would be expected to be around 5.3; if half of it dissolves (and reacts) it would be expected to be around 5.46 and if all of it dissolved and reacted around 5.6. Could that much change in mash pH effect the way the beer tastes? Yes, I expect so but I don't know how much nor do I know how the chalk will behave. I'd guess about half would react.

 

[McKnuckle]

I put your recipe into Brewer's Friend and calculated water additions for just the mash volume of 4.6 gallons.

3g gypsum
1g Epsom
2g CaCl

Gets you a mash pH of 5.36 and nice mineral levels.

No I'm not addressing the sparge, and I'm not getting into all of the academics in the debate above, but to me less is more with water. I don't subscribe to the idea that you need to add a little of everything to it. Just what's needed. With your additions, you had over 200 ppm residual alkalinity and a mash pH of 5.65, which is probably too high.

 

[ajdelange]

Basically what I need to do is get a god dang pH meter instead of throwing from the hip with what Bru'n Water uses as estimations.

... or any other spreadsheet/calculator.

I think with my calculations on Bru'n Water, it said this was a 5.6pH mash.

With chalk? With acid? With chalk and acid?

The way I add my salts is that I add them to half the grist in the MLT then add the other half of the grist and mix thoroughly before adding any water. Once I mash in I do another thorough mixing.

You shouldn't be using chalk for reasons discussed. Eliminate that and all the other salts are quite soluble in water so they should be mixed with the mash water. This way, as soon as it (the water) hits the grain the salt ions are in solution, evenly dispersed if the grist is properly doughed in and ready to go to work.

 

[ajdelange]

I put your recipe into Brewer's Friend and calculated water additions for just the mash volume of 4.6 gallons.

3g gypsum
1g Epsom
2g CaCl

Gets you a mash pH of 5.36 and nice mineral levels.

That's reasonable if you assume pHDI for MO is 5.6 and I have seen it quoted as being that low. I have no idea what Brewer's Friend uses to model MO and the two examples I measured both came in higher than this but at least this is in the ball park and helps put away the highly acid mash theory.

We would do well to remember here that while Kai's measurements may not have reflected the ultimate in precision he was the pioneer. His were the first steps towards the robust theory.

 

[Tutsbrew]

Acrid taste is usually too much roast something. As he totals less than 10% of the chocolate and roast barley he shouldn't have that acrid taste unless one or the other of those roast things is overly ashy. As to the pH: if none of the chalk dissolves the pH would be expected to be around 5.3; if half of it dissolves (and reacts) it would be expected to be around 5.46 and if all of it dissolved and reacted around 5.6. Could that much change in mash pH effect the way the beer tastes? Yes, I expect so but I don't know how much nor do I know how the chalk will behave. I'd guess about half would react.[/quote

You know more about this than I do. I was thinking that 5.3 ml of lactic acid was a lot considering such heavy use of darker grains but I did not take the time to carefully consider it or use a software. On the other hand, 12oz of C120 along with nearly 10% of burnt grains in the grist, IMHO, would make any beer taste acrid! ...Perhaps this is why porters and stouts are not among my fav's.

 

[Tutsbrew]

I put your recipe into Brewer's Friend and calculated water additions for just the mash volume of 4.6 gallons.

3g gypsum
1g Epsom
2g CaCl

Gets you a mash pH of 5.36 and nice mineral levels.

No I'm not addressing the sparge, and I'm not getting into all of the academics in the debate above, but to me less is more with water. I don't subscribe to the idea that you need to add a little of everything to it. Just what's needed. With your additions, you had over 200 ppm residual alkalinity and a mash pH of 5.65, which is probably too high.

Regarding post #3 in this thread, would adding 5.3ml of 88% lactic acid change the mash pH and the resulting taste of the beer? ...Keeping in mind the OP likely did not dissolve the chalk with CO2 or such. This is the burr under my saddle.

I'm intrigued by this thread in that a recent (much smaller) addition of that very acid to a grist that amounted to an SRM of 12 changed the pH quite a bit. That beer was very bad, and I used chalk at that time. Brewers Friend must assume a person will always dissolve the chalk as the software allows the "chalk addition" to change the pH accordingly.... Again, I'm thinking the OP did not dissolve it in the mash water, or at least he did not mention doing so.

Anyway, I now use pickling lime if I need a base when building from distilled water, it dissolves and the ambers/red ales are much, much better. FWIW, the parameters for that beer in Brewers Friend are identical as when I used chalk!

I'm no chemist, but I still find this thread fascinating as some of the thinking runs against my recent experience. Must be brewing in the twilight zone.

Anyone else here use pickling lime for base additions when building from distilled?

 

[ajdelange]

You know more about this than I do. I was thinking that 5.3 ml of lactic acid was a lot considering such heavy use of darker grains but I did not take the time to carefully consider it or use a software.

It is but it's just about the amount that would be required to neutralize the alkalinity of the chalk addition so IF the acid dissolved all the chalk and enough time were allowed for them to react the acid and roast malt additions would pretty much cancel each other out. If less than all of the chalk reacts then there would not be complete cancellation and the pH would drop lower.

On the other hand, 12oz of C120 along with nearly 10% of burnt grains in the grist, IMHO, would make any beer taste acrid! ...Perhaps this is why porters and stouts are not among my fav's.

I don't do many beers using roast malts but when I do Irish stout I use 10% roast barley and it doesn't taste acrid at all - just roasty, coffeelike. OTOH on the few occasions when I have been asked to judge stouts I come home feeling as if I've been browsing in the Kingsford bag.

 

[ajdelange]

Regarding post #3 in this thread, would adding 5.3ml of 88% lactic acid change the mash pH and the resulting taste of the beer?

As stated in earlier responses that would depend on the extent of reaction of the chalk. It reacts slowly. I have seen a suspension of chalk in a water + HCl mix of pH 5 and less. Keep stirring and monitoring and the pH will go up but it takes quite a while.

Keeping in mind the OP likely did not dissolve the chalk with CO2 or such. This is the burr under my saddle.

Doubtless he didn't. That is an exercise which usually turns out to be a waste of time as the chalk just precipitates back out when the pressure is taken off and the water is heated.

I'm intrigued by this thread in that a recent (much smaller) addition of that very acid to a grist that amounted to an SRM of 12 changed the pH quite a bit.

How much the pH will change for a given acid addition depends on the buffering capacity of the malt and that depends both on the particular malt in use (pale ale malt has higher capacity than pilsner malt) and on the pH shift contemplated (buffering is a function of pH).

That beer was very bad, and I used chalk at that time.

That's what I've been told happens when people put chalk in their beers.

Brewers Friend must assume a person will always dissolve the chalk as the software allows the "chalk addition" to change the pH accordingly....

In order to compute the effect on pH the software must know the charge on the carbonate when it is added. For the powder that is -2 mEq/mol. For chalk dissolved the software would have to know the pH of the solution it is dissolved in. That's a fancy way of saying the software has to assume that the chalk is added as powder. In the calculations I did chalk was assumed to have been added as calcium carbonate the salt.

Again, I'm thinking the OP did not dissolve it in the mash water, or at least he did not mention doing so.

In terms of equilibrium conditions it doesn't matter whether he suspended it in water (it will not dissolve) or added it as a powder. Practically speaking what matters is how much of it reacts in the time frame of interest.

Anyway, I now use pickling lime if I need a base when building from distilled water,

That does work better but even it takes some time. For small tweaks and where sodium is not of concern baking soda is best as it reacts fastest.

..it dissolves and the ambers/red ales are much, much better. FWIW, the parameters for that beer in Brewers Friend are identical as when I used chalk!

As far as pH calculation is concerned proton deficit is proton deficit whether it comes from bicarbonate, carbonate, hydroxyl or phosphate. In the making of a mash chalk screws things up by continuing to react after the mash phase is over.

I'm no chemist, but I still find this thread fascinating as some of the thinking runs against my recent experience. Must be brewing in the twilight zone.

Tell us what the experience is and which thinking it seems to conflict with and we can try to explore the discrepancy further. We may run into a problem if you make a statement like 'I added 2.7 mL of lactic acid to my porter and the pH dropped 0.8 and you said it would only drop 0.5' because my response to that would be 'OK, what's the buffering curve for your mash' and you probably won't be able to answer that question so then I'd ask 'What's the alkalinity of your water, how much did you use and what's your malt bill?' If I have measurements for the malts you used or similar malts I can usually come up with a reasonable explanation for what you have seen.

Anyone else here use pickling lime for base additions when building from distilled?

You shouldn't need to use lime or any alkali even with RO water unless
1) Your base malt has low pHDI (<5.6 and some do)
2) You load the water with calcium
3) You use inordinate amounts of high kilned malts.

WRT #3 this means enough that you are getting the acrid tastes referred to earlier in this thread in which case the beer is already, IMO, ruined. But homebrewers are experimenters who like to push the envelope and so I recognize that there will be cases where some alkalinity is required. As stated earlier my first choice would be sodium bicarbonate followed by lime (calcium hydroxide). One of the main discomforts with pickling lime is that it may contain a fair amount of calcium carbonate.

 

[Tutsbrew]

Thanks Ajdelange! ...Have a great week dude.

 

[ajdelange]

Based on these discussions, on the admonition to 'keep working' and the desire to understand how Martin could conclude that OP's mash could be 'EXTREMELY acidic' I've done a little further thinking. I can't experiment with Bru'n Water because in order to use a PC originated Excel spreadsheet on the Mac one has to change all the fonts and as all the cells in Bru'n water are locked I can't do that. But I did find a writeup on Matt Chrispin's website with some screenshots and was able to figure that an acidity number seems to be derived from the type of malt and the color. I'm pretty sure Martin has said this is based on Kai Troester's measurements so a review of those was clearly in order. A quick look at Kai's scatter plot makes it clear that one can fit line segments to acidity vs color in certain regions but its also pretty clear that those fits would not be terribly good ones. I also found out that while the data from Kai that Palmer quotes in the book says the titrations are to 5.4, the plot posted on Kai's website says 5.7. For any malt I have measured I can compute the acidity to pH 5.7 and compare to what Kai found. As an example of this I measured an 80L Briess caramel (that's what it said on the package) malt and found its acidity to be 64 mEq/kg. Kai measured an 90L Briess crystal (does Briess make Caramel and Crystal malts in this range) malt and found its acidity to be 45 mEq/kg pH. Plot those two points on his diagram and they certainly don't lie on a straight line with the other crystal/caramel malts. Not also that on his diagram C60 is more acidic than C120 though it is of lighter color.

Of even more interest are Kai's and my measurements of the same grain: Briess 300L roast barley. Kai got 40 mEq/kg for this and I got 67. We must conclude one or more of the following is responsible:

1) Kai doesn't know how to measure pH
2) I don't know how to measure pH
3) High kilned grains, though similar or the same in color, can exhibit widely disparate acid/base properties.

I hope it is clear that the third possibility is the most likely and the conclusion, obviously, is that a malt type/color model isn't a very good one for mash pH prediction. The obvious question is then as to how are spreadheets such as Bru'n water able to do as well as they do. I think the answer must be that these specialty malts are used in relatively small quantities such that rather large differences between what the program decides the acidity is and what the actual acidity of the malt being used is don't have that much influence. As an example of this taking the OP's grist and mashing it with RO plus 2 grams of CaCl2 we would calculate for Crisp MO and 5.1% Briess roast barley as I measured it a mash pH of 5.495 (you all know that the 3rd decimal place is nonsense and is only there to let you see in detail the change) whereas that same grain, as Kai measured it, about 60% as potent (to pH 5.7 - to pH 5.5 my sample delivers 50 mEq/kg and Kai's about 32), the predicted mash pH rises only to 5.513, a difference of less than 0.02.

Given that the relatively small amounts of specialty malts have but relatively small effect on mash pH, even though they may be quite acidic, we conclude that the major driver in setting mash pH is the base malt and in particular its alkalinity. How does the color model behave here? Looking at Kai's data, apparently better. But not that one point on his plot shows higher acidity for less color. IOW there is variability in base malts as well as colored malts. My finding that MO from Crist and Muntons behave quite differently confirms this. Looking at Kai's scatter diagram we see that all the malts he measured showed positive acidity (negative proton deficit) to pH 5.7. This says that no base malt has a pHDI > 5.7 and that is definitely not true. Of the 9 grains I have characterized thoroughly, two (Weyermanns floor pils and Muntons M.O.) have DI mash pH's greater than 5.7 and, consequently negative acidities WRT that pH. So we WAG base malt properties as having a pHDI of between 5.6 and 5.7 based on a linear assumption over that range of pH and perhaps 5 SRM/°L and go forth. The malts with dipH higher than 5.87 seem relatively rare and so we don't make much error here either as long as we have a good stab at the buffering capacity. Forty mEq/kg-pH is a pretty good guess for that and we can now estimate mash pH fairly accurately (±0.1 pH?) most of the time.

All the above tells us why spreadsheets like Bru'n Water and Brewer's Friend can be off by 0.1 pH but we still have Martin's finding that a grist like the OP's is very acidic. Given the assumption that Bru'n water is based on Kai's measurements and that they tend to be low in their estimation of acidity compared to my measurements, and noting that I don't really have enough measurements to make that an overall observation on Kai's measurements in general but only that for the few comparisons that I have done, it seems unlikely that Bru'n Water would calculate a pH of 5.2 for OP's mash. I therefore assume that Martin is recalling measuring a similar mash or mashes. As noted in an earlier post to see a pH of 5.2 with OPs grist would require a super-acid malt such as a roast barley with the potency of sauermalz. As this is unlikely to exist I have to assume that Martin isn't remembering right, i.e. that the grist he found to have a pH this low had a lot more than 19% colored malts or that he just doesn't remember the numbers right or that the measurement was in error, probably from failure to wait for equilibrium or near equilibrium.

This all is not intended to be critical of Kai or Martin but rather to try to lend insight. Clearly I think improvements can be made (that's what I am working for) and I know this additional insight will help me. I certainly hope, all the typing effort, that it will get others interested too.

 

[BrewerJack]

So basically from all of this discussion I have realized that this isn't as simple as "the reason your beer is **** is because X". I think, at least until I get a good pH meter, I am going to lay off the water profiles for now.

My filtered tap water has done well over the last year and maybe it will hold out.

A few questions still remain:
1. So I should stop with the chalk additions?
2. What is a good pH meter for usage in these conditions?
3. When you sample mash pH, you wasn't it as close to room tempo as possible right? How do you get it there within an amount of time that and acid or base addition would actually be effective?

 

[ajdelange]

So basically from all of this discussion I have realized that this isn't as simple as "the reason your beer is **** is because X".

People want 'sound bite' answers these days but there are none in brewing any more than there are in other aspects of life.

A few questions still remain:
1. So I should stop with the chalk additions?

Yes

2. What is a good pH meter for usage in these conditions?

There's a current thread on that very subject.

3. When you sample mash pH, you wasn't it as close to room tempo as possible right? How do you get it there within an amount of time that and acid or base addition would actually be effective?

Most people dump the sample into something cold like a shot glass that's in the freezer or a small metal pan that can be floated in cold water. Even so it takes a few minutes and coupled with the fact that one must often wait several minutes for the mash pH to settle after an acid or base addition we see that correcting in the mash tun isn't the best way to operate though it is better than not correcting at all. It is preferable to make a test mash using about a pound of grist and tweak that for desired pH. The acid addition can then be scaled to the full mash size.

 

[ajdelange]

In #19 I noted that malt acidity/alkalinity data derived from color isn't very accurate and offered the thesis that this doesn't matter because those malts are used in small quantities relative to base malts so that if fairly good knowledge of the base malts were available the poor data on the specialty malts wouldn't matter. To explore this idea further I took the OP's grist in straight RO - no salts at all and using my measured and Kai's derived pHDI's and bufferings (linear term only) computed a mash pH of 5.56. Then I did 100,000 mashes in which it is assumed that there are errors in the malt parameters (these errors being caused by the rather poor color model) to the extent of standard deviation of 0.05 pH in the base malt and 0.1 in the specialty malts and standard deviations of 5 mEq/kg-pH in the base malt buffering and 10 mEq/kg-pH in the specialty malt buffering. IOW we know the base malt parameters twice as accurately as the specialty malt parameters.

The attached histogram shows the relative frequencies of predicted mash pH's under the error model described above. Note that the preponderance of estimates are within ±0.05 pH of the 'true' pH. There are probably several conclusions we can draw from this histogram but that the original thesis that it doesn't matter that the specialty malts are poorly modeled doesn't much matter is supported is definitely one of them. Of course in the robust model where the actual malt data is to hand one should be able to do appreciably better but then the question is as to how well, as a practical matter, one needs to do. The other comment is that when I use the robust model but haven't tested the actual malt being used I must guess that the properties of the particular malt are similar to something I have measured. That's probably not any better than guessing based on color (not, certainly, in the case of the two roast barley samples measured by me and Kai).

 

[mchrispen]

I do want to revisit a more basic premise... which is potential flavor impact of a robust reaction between alkali and acid.

That is, do not add an acid into the mash when using an alkali. They counteract each other, and if one is not careful, the reaction can be very strong and localized to one small section of the overall mash...

I was playing around with some ideas regarding this (working up an experiment for a possible paper) and have noticed two things that are in play:

1.) Most of the alkali options that we have available rapidly degrade, even baking soda. I have been measuring the effectiveness of my pickling lime (stored in it's mylar bag and in a vacuum sealed jar) and seeing that samples left out will lose viability in just a few hours (a small loss of effectiveness but measurable). I question our ability to isolate differences in quality of our alkali minerals at the homebrew scale. Liquid acid appears more stable. So, a stretch because I need to verify my observations - I believe freshness and careful handling of our minerals is important from a repeatability perspective.
2.) Acid/Alkali reactions in DI water always seem to produce visible precipitate or in some cases a floating scum. I assume that this is simply filler or impurities from using non-lab grade minerals and acids - but my assumption may not be accurate. Water (RO or DI) will take on a distinct flavor once this reaction has occurred (lactic acid and baking soda) that is different than just an acid addition or just an alkali addition, where the pure chemistry would suggest the resulting ion load would merely be a small amount of sodium, a moderate amount of bicarbonate and some lactic ions. I did this experiment setting the sodium load below 40 ppm and allegedly below flavor threshold. This leads me to believe there MAYBE additional chemistry occuring releasing impurities in the acid & alkali addition and concentrated if the mineral additions are not thoroughly dissolved before the introduction of the grist and/or any alkali addition... quantifying that into beer, no ideas.

I am convinced that grocery Baking Soda is not as 'pure' as we maybe led to believe. Pickling Lime is clearly not 'pure' and has stability issues - taking on humidity and degrading to chalk. We have covered the impurity levels in different calcium chloride and even magnesium sulfate before. I guess, if we accept this is good enough for home brewing, what is our expectation of accuracy in the brewhouse? I am happy with 0.1 accuracy in practice and thrilled when my numbers hit under 0.05 pH units in either direction. Just so many possible variables, including errors in dry weight measurement...

Just tossing the idea into the hat.

 

[ajdelange]

I do want to revisit a more basic premise... which is potential flavor impact of a robust reaction between alkali and acid.

At first blush of course the reaction is simply neutralization which produces water and a salt. Thus is one adds hydrochloric acid to a solution of baking soda one gets water and sodium chloride (plus in this case CO2 gas which escapes). Thus a brewer who adds baking soda and hydrochloric acid (CRS) could save himself trouble and expense by just adding table salt instead.

That is, do not add an acid into the mash when using an alkali. They counteract each other,

Certainly one wastes his time (and chemicals) if the goal is pH adjustment but I suppose we could argue that a brewer who is out of gypsum, for example, could add lime and sulfuric acid.

...and if one is not careful, the reaction can be very strong and localized to one small section of the overall mash...

There isn't likely to be a violent reaction unless concentrated sulfuric acid is used and there the violence is attributable to sulfuric acid's affinity for water, not the acid base neutralization. The evolution of CO2 when carbonate or bicarbonate is neutralized I wouldn't consider very strong unless confined. The fact that it may be localized shouldn't be a problem as the products are water and a salt. Naturally, we'd want those to be well mixed in but we'd be stirring the mash anyway.

1.) Most of the alkali options that we have available rapidly degrade, even baking soda.

How could that degrade by which I mean what are the degradation products? The answer is, at higher temperature:

2NaHCO3 ---> Na2CO3 + H2O + CO2

Which can take place above 50 °C (122 °F) if slowly. It takes place rapidly above 200 °C, hence the dry baking soda fire extinguisher. So I guess it could take place very, very slowly at room temperature.

Clearly if it takes on moisture to the extent of 5% of the total weight then its potency is 95% that of sodium bicarbonate just out of the dessicator. Is this what you mean?

I have been measuring the effectiveness of my pickling lime (stored in it's mylar bag and in a vacuum sealed jar) and seeing that samples left out will lose viability in just a few hours (a small loss of effectiveness but measurable).

To make lime one heats calcium carbonate

CaCO3 --> CaO + CO2
CaO + H2O -----> Ca(OH)2

and these reactions can work in reverse in fact that is what is responsible for the curing of concrete so we would expect some conversion of lime back to CaCO3 over time but hours? They only turned off the cooling water at the Hoover dam a few years ago. Again I can see pickup of water by lime with a few percent reduction in apparent strength by weight caused by this. I think a more pertinent question may be as to the purity of these salts when we buy them.

I question our ability to isolate differences in quality of our alkali minerals at the homebrew scale.

Most of us do not have assaying ability. We are more concerned that the stuff we buy is FCC and less that it is ACS grade. There is a pretty sensitive test for the strength of any alkali though and that is the alkalinity test. 168 mg of sodium bicarbonate should produce a liter of solution with an alkalinity of 102.5 (pH 4.3 endpoint) as should 124 mg of sodium carbonate monohydrate. And the same for 74 mg of lime or 100 mg of calcium carbonate. If we dissolve 74 mg of lime in a liter of water and get less that 102 ppm alkalinity in testing that water we can conclude that some got converted to CaCO3 or that the powder picked up some water from the air or both but we can't really tell which without more sophisticated testing (drying in a moisture balance, quantitative assessment of the CO2 produced during the titration).

Liquid acid appears more stable.

I have an old bottle of lactic acid. It has turned brown. So some kind of degradation has taken place. If I take the cap off a jug of hydrochloric acid indoors I regret it. When I used to work in a plant where the drawings were reproduced by the Diazo process involving ammonia gas the whole engineering section became enshrouded in an ammonium chloride fog on the days they delivered HCl (by tanker truck) to the plant. The point being that HCl gas leaves hydrochloric acid thus clearly resulting in a reduction in its strength.

So, a stretch because I need to verify my observations - I believe freshness and careful handling of our minerals is important from a repeatability perspective.

It's just good practice. I wouldn't worry too much about sodium bicarbonate and I would worry a great deal about calcium chloride. When experimenting with that I happened to notice that the calcium carbonate jar was labeled "Caution: hygroscopic" so even that can pick up water from the air.

2.) Acid/Alkali reactions in DI water always seem to produce visible precipitate or in some cases a floating scum. I assume that this is simply filler or impurities from using non-lab grade minerals and acids - but my assumption may not be accurate.

If you 'neutralize' carbonic or phosphoric acid with lime eventually you will get precipitation of chalk or apatite. But if you neutralize lactic acid with lime you shouldn't. You will get lactate ions, calcium ions and water. As calcium lactate is quite soluble there will be no precipitation. If your 'lime' was 50% calcium carbonate, that would precipitate (or rather never dissolve in the first place).

Water (RO or DI) will take on a distinct flavor once this reaction has occurred (lactic acid and baking soda) that is different than just an acid addition or just an alkali addition, where the pure chemistry would suggest the resulting ion load would merely be a small amount of sodium, a moderate amount of bicarbonate and some lactic ions. I did this experiment setting the sodium load below 40 ppm and allegedly below flavor threshold. This leads me to believe there MAYBE additional chemistry occuring releasing impurities in the acid & alkali addition and concentrated if the mineral additions are not thoroughly dissolved before the introduction of the grist and/or any alkali addition... quantifying that into beer, no ideas.

A solution of sodium lactate is going to taste different than a solution of lactic acid alone. Lower pH for one thing and you will also have the synergistic influence of both sodium and lactate.

I am convinced that grocery Baking Soda is not as 'pure' as we maybe led to believe.

Arm and Hammer baking soda is advertised as 100% pure and checking out descriptions of how it is made reveal that the process produces product of greater than 99% purity. OTOH note that one of the common uses of baking soda is to absorb unpleasant odors in your refrigerator. I'm sure that this amounts to ppm level pickup, however.

Pickling Lime is clearly not 'pure' and has stability issues - taking on humidity and degrading to chalk.

Taking up moisture happens to anything. This problem can be solved by drying in an oven and, preferably cooling in a dessicator before weighing. The conversion to calcium carbonate I'm not so sure about but the chemistry suggests that it will take place eventually. What I question is the extent. I've not seen a sample fizz under acid, for example

We have covered the impurity levels in different calcium chloride

The big impurity there is water though calcium chloride does contain traces of sodium and other metal ions.

..and even magnesium sulfate before. I guess, if we accept this is good enough for home brewing, what is our expectation of accuracy in the brewhouse? I am happy with 0.1 accuracy in practice and thrilled when my numbers hit under 0.05 pH units in either direction. Just so many possible variables, including errors in dry weight measurement...

It appears from my most recent post here that we are, at best, guessing at mash pH and that our guesses are going to be within ±0.1 pH if we are at all reasonable about what we think the average properties of the malts we use may be. Suppose we take the grain bill of the OP (remember that?) and add enough acid to reduce the mash pH to 5.4. Now lets suppose the acid isn't full strength but only 75% of what we think it is. The estimated pH shifts to 5.44. IOW the error introduced by 25% error in knowledge of acid strength (or error in measuring it out) has but a small effect on the pH estimate. Less, certainly, than poor estimates of grain pHDI and buffering based on color (most spreadsheets) or assuming that the 60L crystal malt you bought this year in Texas is the same as the 60L crystal malt I measured two years ago in Virginia (robust approach).

 

[McKnuckle]

I would just like to say to the OP, if by small small chance he is still checking this thread, to not despair. One need not be a hydrologist or chemist to assess and adjust brewing water to one's needs.

There are a few folks here that are enthusiastic experts on the topic, some of whom have even done pioneering experimental work that has benefitted homebrewers. They tend to jump in to all water threads with both feet and possibly hands too. Sometimes it's helpful, other times it muddies the waters (pun!).

There are some simple guides available on this topic and I encourage you to read them. Palmer's online How To Brew site has a water section. There's a sticky post on this forum as well. Googling will get you other resources.

For me personally, I don't try to match historical water profiles too closely. I go for achieving reasonable mineral concentrations based on what's published - not too much, not too little, but "just right." For example, they say that Calcium should be at least 50, but not too much over 100. Okay, so we'll go for 75. We don't stress if it's 65 or 80. Also, I can't explain why it's "just right," but I don't have to: I trust the work of others and use the tools in a practical way.

I use the Brewer's Friend water calculator because I like how you can use trial and error - you enter your own guesses at salt additions, recalculate, and see what it gives you. I think that teaches you about the interactions and cause/effect of each salt, moreso than a program that magically states how much of each salt to add in order to achieve a pre-determined profile. With that kind of tool, you don't really see which salt does what. Brewer's Friend makes it easy to see.

At the end of the day, I use two water sources - distilled and my own well water (high sodium, chloride, and bicarbonate, low sulfate). And I use four additives - gypsum, calcium chloride, Epsom, and lactic acid. Between blending the waters and ameliorating with additives, I am able to brew everything from the lightest lager to the darkest stout.

 

[bragona71]

very interesting thread!! makes me second guess my water additions.

 

[mchrispen]

My apologies to the OP... the topic has drifted and probably not all that helpful, but I think a healthy discussion otherwise.

AJ - I might drop you an email with some thoughts. Maybe a matrix of reactions and expected results could be useful... based on normally used minerals and liquid acids in home brewing. As for the hydroscopic effects... that is what I am primarily referring... I am just now experimenting with calcium chloride solution rather than dry weight.

 

[BrewerJack]

Oh don't apologize. Good discussion by all. I never thought being chemistry was still in such a state of flux.

Very enlightening.

 

[mchrispen]

Not so much in flux, rather dealing with differing approaches to a problem, as well as with the inherent inaccuracies of doing this in one's backyard or garage, as well as my amateur observations and lack of legit vocabulary.